Industrial process industries primarily rely upon energy sources that include one or more combustion processes. Such combustion processes include operation of a furnace or boiler to generate energy from combustion, which is then used for the process. While combustion provides relatively low-cost energy, its use is typically regulated and combustion efficiency is sought to be maximized. Accordingly, one goal of the process management industry is to reduce the production of greenhouse gases by maximizing combustion efficiency of existing furnaces and boilers.
In situ or in-process analyzers are commonly used for the monitoring, optimization, and control of combustion processes. Typically, these analyzers employ sensors that are heated to relatively high temperatures and are operated directly above, or near, the furnace or boiler combustion zone. Combustion analyzers, such as those sold under the trade designation Oxymitter or Model 6888 Combustion Flue Gas Transmitter available from Rosemount Analytical, Inc. of Solon, Ohio (a business unit of Emerson Process Management), often employ zirconia oxide sensors heated to a temperature above approximately 700° Celsius (1300° Fahrenheit).
In situ analyzers generally employ a sintered metal filter or other diffuser positioned between a measurement cell and the process combustion gas to allow the process combustion gas to diffuse to the measurement zone while minimizing flow effects and reducing measurement cell contamination. The diffuser readily allows the process combustion gas to contact the heated measurement cell. However, if the diffuser should become partially or fully plugged, it can introduce errors into the measurement. Thus, providing an in situ oxygen probe that is better able to diagnose diffuser obstructions and/or compensate for effects of such obstructions would advance the art of process analytic measurement and control.